Gear-shift control and gear-range selector for a semi-automatic or fully-automatic motion vehicle gearbox

ABSTRACT

In a motor vehicle having a transmission (1) which can be optionally operated fully automatically or semi-automatically, and in which a gear-range selector (18) and a gear-shift control (21) are provided. The gear-range selector makes it possible to pre-select a travel speed in which the transmission is gradually shifted up or down by actuating the gear-shift control (21). The gear-shift control (21) is designed as a foot switch (22, 24) located in the foot area of a driver&#39;s cab of the motor vehicle, so that both of the driver&#39;s hands can stay on the steering wheel while these gear-shift operations are being carried out thereby permitting the driver to concentrate fully on the traffic.

The invention concerns a gear and gear-range selector for asemi-automatic or fully automatic motor vehicle transmission wherein aspeed range is adjustable by means of the gear-range selector, in whichthe transmission can be manually shifted up or down by a single gearspeed via the gear-shift control.

DE-A 40 06 653 has disclosed a gear and gear-range selector of the abovementioned kind. The gear-range selector with which the driver canpre-select different shifting cycles such as a fully automaticoperation, a manual operation, a reverse travel position, a neutralposition, etc., is optionally designed as a rotary or push-buttonswitch. The gear-shift control, through which the driver transmits shiftcommands to an electronic control unit in the manual or semi-automaticoperation of the transmission, is designed as a steering column selectoror as a manually operable console selector. The gear most favorable forthe traveling condition concerned is determined by the control unit fromthe speed, the load and the acceleration values combined with an engineperformance graph and optically indicated to the driver. By actuatingthe gear-shift control into a first plane of motion, the driver releasesthe shift of the recommended gear. If the driver moves the gear-shiftcontrol to a second plane of motion, which extends across the firstplane of motion, manual upshifts and downshifts of the transmission arereleased by a single gear speed. In addition, reverse shifts of thetransmission can also be released by means of a kick-down switchprovided on the acceleration pedal. The disadvantage of this deviceconsists in that the operation of the gear-shift control designed as asteering wheel or console switch makes special attentiveness of thedriver necessary, it being impossible for both hands to stay on thesteering wheel.

Therefore, the problem to be solved by this invention is to provide agear and gear-range selector which is easy to operate and enables thedriver to fully concentrate on the traffic.

In a gear and gear-range selector of the above mentioned kind, saidproblem is solved according to the characteristic part of claim 1, bythe fact that the gear-shift control is designed as a foot switchlocated in the foot area of the motor vehicle. It is possible with thefoot switch, depending on the position of the gear-range selector, torelease manual shifts by a single gear speed or automatic shifts intothe gear speed that the control electronics have assessed as optimal.The driver can then fully concentrate on the traffic and leave bothhands on the steering wheel during a manual shift or release of a shiftinto an automatically pre-selected gear.

The publication DE-A 37 17 675 has disclosed a combined gear andgear-range selector having a selector lever movable in two shift gates.Pre-selected positions in one shift gate are for a fully automaticoperation, upshift limiting steps and a parking, a reverse gear and aneutral position of the transmission, respectively. The selector levercan be moved via a crossgate into the second shift gate in which thetransmission is gradually and manually shifted up or down. The manualshifting of the transmission likewise requires great attentiveness ofthe driver who can steer the vehicle with only one hand during thisoperation.

The publication SAE Technical Paper Series 831776 "Automated MechanicalTransmission Controls"--Nov. 7 to 19, 1983, pages 2, 6 and 7, hasdisclosed a combined gear-range selector and gear device which has aselector lever movable in a gate extending in the longitudinal directionof the vehicle. The selectable positions include a position for a manualoperation of the transmission in which the gear shift last engaged bythe automatic system is preserved. In the manual position, the selectorlever can be moved by hand in two different directions across theselector gate whereby the transmission is gradually shifted up or down.In this device, the driver must also seek an adequate position on theselector lever in which a manual shifting of the transmission ispossible, his attentiveness is thus diverted from the street traffic.Since the driver must manually carry out the corresponding changes, bothhands cannot remain on the steering wheel.

Other advantageous embodiments of the invention are described below.

According to one embodiment of the invention, the foot switch shouldhave a shift rocker movable about a horizontal swivel axis and whoserocker halves cooperate with contacts respectively for shifting up ordown, respectively. In this connection it is provided to arrange theshift rocker with its swivel axis extending across the travel directionof the motor vehicle so that the driver releases and upshifts with thetip of his foot on the front half of the rocker, and downshifts with hisheel on the rear half of the rocker. The shift rocker can here bedesigned in a manner such that the driver momentarily traces by a hapticsignal that the change-over command has been received by the electroniccontrol unit. In addition, the shift rocker can be provided with meanswhich allow the shift rocker to return to its neutral position aftereach change-over command before another change-over command is given.

Alternatively, the foot switch can be designed as a pressure switch, theduration of actuation of the pressure switch being determined via atime-function element and synchronized with a desired upshift ordownshift. In this way it could be possible, to shift down via a brieftouch of the pressure switch while holding the pressure switch in itsactuation position longer results in a shift up the transmission.

According to another embodiment, the gear-range selector must have aselector lever movable in a selector gate, said selector lever havingpositions in said selector gate for a fully automatic operation AS, amanual operation M, an ASM operation in which upon actuation of the footswitch an optimal gear shift determined by an electric gearshiftselection is directly engaged, a neutral position N and a reverse speedrange R. The motor vehicle is here essentially operated in the positionsfor fully automatic operation AS, operation with direct shift into anoptimal gear speed ASM, and manual operation M, said positionspreferably adjacent each other so as to require only a brief actuationpath of the selector lever and slight attentiveness of the driver duringthe selection operation.

In this connection, the selector gate can be given an L-shaped designwherein the positions for fully automatic and manual operations,engagement of the optimal gear and neutral are correspondingly arrangedsuccessively in a common selector gate and wherein a position for thereverse gear range is situated at the end of a transverse gate attachedthereto. The forward and reverse gear ranges are thus separate from eachother and incorrect operations can therefore be prevented. The firstselector gate with which the forward positions are coordinated can besituated in the motor vehicle across the travel direction thereof.

In a further development of the invention, in a reverse travel positionof the gear-range selector an engagement of the reverse gear can bemanually carried out with the foot switch. The reverse gear of thetransmission can be engaged only when the motor vehicle is parked andthe emission of a shift command from the electronic control unit isconveniently suppressed via a safety device as long as the motor vehiclemoves forward.

In addition, the transmission can be switched down by one gear shiftinto a fully automatic operation by a single actuation of the footswitch. Such a design of the device has the advantage that beforeoverhaul operations and before running over hills, it is possible toshift the transmission down by one gear shift without special cost ofcircuit. The switch back, can be canceled by repeated actuation of thefoot switch or according to a time function.

The invention is not limited to the combination of features of theclaims. Other possible logical combinations result to a skilled personfrom the claims and separate features of the claims in accordance withthe existing problem.

For further explanation of the invention, reference is had to thedrawing in which an embodiment is shown in simplified form.

In FIG. 1 a transmission, which can be designed as a countershaft orplanetary transmission is designated with a 1. The transmission isdriven by an internal combustion engine, not specifically designated,and, when designed as a countershaft, an automated master clutch issituated between the internal combustion engine and the transmission 1.The transmission 1 has four gear selection shift cylinders 2 whichinteract with shift clutches situated in the interior of thetransmission 1. With the cylinders 2, the same as other shift orselector cylinders not shown in the drawing, are synchronized solenoidvalves 3, a main shift valve 4 and shift valves 5 and 6. The valves 3 to6 are electrically controlled by an electronic control unit 7.Pressurized air in a pneumatic accumulator or pressure broiler 8 is madeavailable which is fed to the shift cylinders 2 via the electricallycontrolled valves 3 to 6. A hydraulic fluid can obviously be provided asthe actuation means instead of pressurized air.

An electric line 9, attached to the electronic control unit 7, transmitsmeasured values and shift signals to the electronic control unit 7, andpressure sensors are attached to the electric line 9, specifically, onespeed sensor 10 for determining the speed of the internal combustionengine, a speed sensor 11 for determining an input speed of thetransmission and a speed sensor 12 for determining an output speed ofthe transmission. The electronic control unit 7 emits shift signals tothe valves 3 to 6 via electric line 13.

A steering wheel 14 with a steering column 15 is situated in a driver'scab or a passenger cell of the motor vehicle. An accelerator or drivepedal 16 is also in the foot area of the driver's cab, which, as a loadcell, adjusts a throttle valve, not shown, in Otto engines, or a controlrack or an injection pump in diesel engines. The drive or acceleratorpedal 16 can be directly coupled mechanically to the throttle valve orcontrol rack, or an electronic coupling (E-gas) is provided. Inaddition, the accelerator pedal 16 works together with a kick-downswitch 17 which, in case of a quick actuation of the accelerator pedal16, releases a reverse shift of the transmission 1 via the electroniccontrol unit 7.

A gear-range selector 18, designed as a console selector and whoseselector lever 19 serves for pre-selecting specific travel programs, isalso situated in the driver's cab of the motor vehicle. In the drawing,above said selector lever 19, is shown as an L-shaped gate course withwhich gear-range positions are synchronized, AS for a fully automaticoperation, M for a manual operation, ASM for an operation with directshifting to an optimal gear-range level selected by a shifting system ofthe electronic control unit 7, N for a neutral position, and R for areverse travel position.

An indicator 20, likewise connected with the electronic control unit 7,shows the precisely engaged gear of the transmission and, in the ASMposition of the selector lever 19 and parallel therewith, a recommendedoptimal gear speed is indicated.

A gear-shift control 21 is likewise located within the foot area of thedriver's cab of the motor vehicle. The gear-shift control 21 isactuatable by the driver with the left foot and is likewise connectedwith the electronic control unit 7. In the M position, for manualoperation of the gear-range selector 18, a gradual upshift or downshiftof the transmission 1 is carried out by different manipulations. Twodifferent embodiments of the gear-shift control 21 are shown in thedrawing.

According to a first proposal, the gear-shift control 21 must have ashift rocker 22 which has a central swivel axis 23. If the driver stepson a rocker half 22A of the shift rocker, a corresponding closing of acontact, not shown, leads to a shifting up of the transmission 1 by onegear speed. When stepping on a rocker half 22B, the transmission 1correspondingly shifts down by one gear speed.

If the selector lever 19 of the gear-range selector 18 is in the ASMposition, the shift to a gear regarded as optimal by the electroniccontrol unit 7 is also effected by actuating the shift rocker 22. If thetransmission 1 is fully automatically controlled as a result of speedand load signals in the position AS of the selector lever 19, the drivercan voluntarily interrupt the control for a certain period of time priorto overhaul operations or when running over hills. In this case, thedriver must only briefly actuate the gear-shift control 21 and thetransmission is then switched by one gear speed. After a certain periodof time, this condition of operation of the control device is againautomatically canceled or it can be provided that the operationcondition be canceled by a repeated stepping on the shift rocker.

In the drawing is shown another possible embodiment of the foot switch,that is, the gear-shift control 21 is shown in broken lines. What isshown here is a pressure switch 24 connected with the electronic controlunit 7 via a time-function element 25. Depending on the duration of theactuation of the pressure switch 24, which is determined by thetime-function element 25, it is established whether a desired upshift ora desired downshift of the transmission 1 is necessary.

It is to be understood from the drawing that with the gear-shift control21 designed as foot switch 22 or 24, the driver can, in a simple manner,issue shift commands to the electronic control unit 7 without beingdistracted from concentrating on driving. It is of a special advantagehere that the gear-range selector 18 be separately arranged as a consoleswitch through which no shift commands are issued. As shown byexperience, a combination of gear-shift control 21 and gear-rangeselector 18 within a control lever often actually results in incorrectoperations and requires great attentiveness of the driver.

Reference Numerals

1 transmission

2 shift cylinder

3 solenoid valve

4 main shift valve

5 shift valve

6 shift valve

7 electronic control unit

8 pneumatic accumulator

9 electric line

10 speed sensor

11 speed sensor

12 speed sensor

13 electric line

14 steering wheel

15 steering column

16 accelerator pedal

17 kick-down switch

18 gear-range selector

19 selector lever

20 indicator

21 gear-shift control

22 shift rocker

23 swivel axis

24 pressure switch

25 time-function element

We claim:
 1. A gear shift control and range selector for asemi-automatically and fully automatically operated transmission (1) ofa motor vehicle comprising:a gear range selector (18) beinginterconnected with a control means (7) for sending signals to saidcontrol means upon an actuation of said selector (18), upon receipt ofsignals from said selector (18) said control means determines a desiredspeed within which said transmission can be shifted up and down by asingle gear shift; a gear shift foot switch (21) being located in a footarea of the motor vehicle comprising a shift rocker (22) having ahorizontal swivel axis (23) dividing said shift rocker (22) into tworocker halves (22a, 22b) that selectively contact and actuate respectivecontacts, said contacts being interconnected with said control means forsending signals to said control means (7) upon actuation of saidcontacts; and said control means (7) being interconnected with a gearshift means (2-6) for sending signals to said gear shift means (2-6)upon receipt of signals from said contacts, thereby activating said gearshift means (2-6) to shift said transmission up and down.
 2. Anapparatus according to claim 1, wherein said gear-range selector (18)has a selector lever (19) movable in a selector gate, said selectorlever (19) has positions in said selector gate for a fully automaticoperation (AS), a manual operation (M), a semi-automatic operation (ASM)in which said control means (7) determines an optimal gear speed and,only upon actuation of said foot switch (21), said control means sends asignal to said gear shift means (2-6) to shift said transmission to saidoptimal gear speed, a neutral (N), and a reverse speed (R).
 3. Anapparatus according to claim 2, wherein said selector gate is situatedin the motor vehicle across the travel direction thereof.
 4. Anapparatus according to claim 1, wherein, in a reverse travel position(R) of said gear-range selector (18), said control means (7) sends asignal to said gear shift means (2-6) to shift the reverse gear inresponse to a signal from said foot switch (21).
 5. An apparatusaccording to claim 1, wherein, in a fully automatic operation position(AS) of said gear-range selector (18), said control means sends a signalto said gear shift means (2-6) to shift said transmission (1) down byone gear in response to a signal from said foot switch (21).
 6. A gearshift control (21) and gear range selector (18) for a semi-automaticallyand fully automatically operable transmission (1) of a motor vehiclecomprising:a gear shift control foot switch (21) being located in a footarea of the motor vehicle, said foot switch comprising a pressure switch(24) and a time-function element (25) that measures the duration of anactivation of said pressure switch (24), said time function elementbeing interconnected with a control means (7) for sending signalscorresponding to said duration to said control means (7); and saidcontrol means (7) being interconnected to a gear shift means (2-6) forsending signals said gear shift means (2-6) upon receipt of signals fromsaid time function element, thereby activating said gear shift means(2-6) to shift said transmission one of up and down depending on saidduration.
 7. An apparatus according to claim 6, comprising:a gear rangeselector (18) being interconnected with said control means (7) forsending signals to said control means upon an actuation of said selector(18), upon receipt of signals from said selector (18) said control meansdetermines a desired speed within which said transmission can be shiftedup and down by a single gear shift; wherein said gear-range selector(18) has a selector lever (19) movable in a selector gate, said selectorlever (19) has positions in said selector gate for a fully automaticoperation (AS), a manual operation (M), an semi-automatic operation(ASM) in which said control means (7) determines an optimal gear speedand, only upon receipt of a signal from said foot switch, sends a signalto said gear shift means (2-6) to shift said transmission to saidoptimal gear speed, a neutral (N), and a reverse speed (R).
 8. Anapparatus according to claim 6, comprising:a gear range selector (18)being interconnected with said control means (7) for sending signals tosaid control means upon an actuation of said selector (18), upon receiptof signals from said selector (18) said control means determines adesired speed within which said transmission can be shifted up and downby a single gear shift; wherein, in a reverse travel position (R) ofsaid gear-range selector (18), said control means sends a signal to saidgear shift means (2-6) to shift the reverse gear in response to a signalfrom said foot switch (21).
 9. A gear shift control and range selectorfor a semi-automatically and fully automatically operated transmission(1) of a motor vehicle comprising:a gear shift foot switch (21) beinglocated in a foot area of the motor vehicle, said foot switch comprisinga shift rocker (22) having a horizontal swivel axis (23) extendingacross a direction of travel of the motor vehicle dividing said shiftrocker (22) into front and rear halves (22a, 22b) that, upon actuationof the shift rocker by a driver's foot, selectively contact and activatefront and rear contacts, said contacts being interconnected with acontrol means (7) for sending corresponding signals to said controlmeans (7) upon actuation of said contacts; and said control means (7)being interconnected to a gear shift means (2-6) for sending signals tosaid gear shift means (2-6) upon receipt of signals from said contacts,wherein, when the driver upshifts by pressing with his foot tip on thefront rocker half and thereby activating said front contact, saidcontrol means sends a signal to said gear shift means (2-6) to shiftsaid transmission up, and when the driver downshifts by pressing withhis heel on the rear rocker half and thereby activating of said rearcontact, said control means (7) sends a signal to said gear shift means(2-6) to shift the transmission down.
 10. A gear shift control and rangeselector for a semi-automatically and fully automatically operatedtransmission (1) of a motor vehicle comprising:a gear range selector(18) being interconnected with a control means (7) for sending signalsto said control means upon an actuation of said selector (18), uponreceipt of signals from said selector (18) said control means determinesa desired speed within which said transmission can be shifted up anddown by a single gear shift; a gear shift foot switch (21) being locatedin a foot area of the motor vehicle, said foot switch comprising a shiftrocker (22) having a horizontal swivel axis (23) extending across adirection of travel of the motor vehicle dividing said shift rocker (22)into two rocker halves (22a, 22b) that, upon actuation of the shiftrocker by a driver's foot, selectively contact and activate respectivecontacts, said contacts being interconnected with said control means (7)for sending corresponding signals to said control means (7) uponactuation of said contacts; and said control means (7) beinginterconnected to a gear shift means (2-6) for sending signals to saidgear shift means (2-6) upon receipt of signals from said contacts,wherein, in response to signals received from said contacts said controlmeans sends signals to said gear shift means (2-6) to shift saidtransmission (1) up and down; wherein said gear-range selector (18)comprises a selector lever (19) movable in an L-shaped selector gateformed of a common selector gate and a cross gate located at the end ofthe common gate, said selector lever (19) has positions spaced alongsaid common selector gate for (i) a fully automatic operation (AS), (ii)a manual operation (M), (iii) a semi-automatic operation (ASM) in whichsaid control means (7) determines an optimal gear speed and, only uponreceipt of a signal from said foot switch, sends a signal to said gearshift means (2-6) to shift said transmission to said optimal gear speed,and (iv) a neutral (N), and said selector lever has a position at an endof the cross gate opposite said common gate for a reverse speed (R). 11.A gear shift control and range selector for a semi-automatically andfully automatically operated transmission (1) of a motor vehiclecomprising:a gear range selector (18) being interconnected with acontrol means (7) for sending signals to said control means upon anactuation of said selector (18), upon receipt of signals from saidselector (18) said control means determines a desired speed within whichsaid transmission can be shifted up and down by a single gear shift; agear shift foot switch (24) being located in a foot area of the motorvehicle, said foot switch comprising a pressure switch (24), saidpressure switch being interconnected to said control means for sending asignal to said control means (7) upon actuation of said foot switch; andsaid control means (7) being interconnected with a gear shift means(2-6), wherein, in a fully automatic operation position (AS) of saidgear-range selector (18), upon an actuation of said foot switch (24)said control means (7) sends a signal to said gear shift means (2-6) toshift said transmission (1) down by one gear and upon a repeatedactuation of said foot switch (24) said control means (7) sends a signalto said gear shift means (2-6) to cancel a downshift of saidtransmission (1).
 12. A gear shift control (21) and gear range selector(18) for a semi-automatically and fully automatically operabletransmission (1) of a motor vehicle comprising:a gear range selector(18) being interconnected with a control means (7) for sending signalsto said control means upon an actuation of said selector (18), uponreceipt of signals from said selector (18) said control means determinesa desired speed within which said transmission can be shifted up anddown by a single gear shift; a gear shift control foot switch (21) beinglocated in a foot area of the motor vehicle, said foot switch comprisinga pressure switch (24) and a time-function element (25) that measuresthe duration of an activation of said pressure switch (24), said timefunction element being interconnected with said control means (7) forsending signals corresponding to said duration to said control means(7); said control means (7) being interconnected to a gear shift means(2-6) for sending signals to said gear shift means (2-6) upon receipt ofsignals from said time function element, thereby activating said gearshift means (2-6) to shift said transmission one of up and downdepending on said duration; and wherein, in a fully automatic operationposition (AS) of said gear-range selector (18), upon an actuation ofsaid foot switch (24) said control means (7) sends a signal to said gearshift means (2-6) to shift said transmission (1) down by one gear.